Display device

ABSTRACT

A display unit of a display device includes a light emitting unit and a light converting layer disposed on the light emitting unit. The display unit emits an output light under an operation of the highest gray level, and the output light has an output spectrum. An intensity integral of the output spectrum from 380 nm to 489 nm defines as a first intensity integral, an intensity integral of the output spectrum from 490 nm to 780 nm defines as a second intensity integral, a ratio of the first intensity integral over the second intensity integral defines as a first ratio, and the first ratio is greater than 0% and less than or equal to 7.5%.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. application Ser.No. 15/623,402, filed on Jun. 15, 2017, which claims the benefit of U.S.Provisional Application Ser. No. 62/462,999, filed Feb. 24, 2017 andU.S. Provisional Application Ser. No. 62/479,326, filed Mar. 31, 2017,all of which are hereby incorporated by reference in their entirety.

BACKGROUND OF THE DISCLOSURE 1. Field of the Disclosure

The present disclosure relates to a display device, and moreparticularly to a display device capable of generating green light whichhas a color close to the green primary color of DCI-P3 color gamut.

2. Description of the Prior Art

Display devices are configured to convert acquired or stored electricinformation into visual information and display it to a user. The colorgamut of display devices, such as cathode ray tube (CRT) display andliquid crystal display (LCD), are referenced to NTSC (NationalTelevision System Committee) color gamut. With the advance oftechnology, in order to meet different color systems and display variouscolors, different color gamuts, such as sRGB, DCI(Digital CinemaInitiatives)-P3 and Rec. 2020 (ITU-R Recommendation BT.2020), have beendefined. The DCI-P3 color gamut is one of the popular color gamuts andis widely applied to various digital monitors or TV.

However, the color temperature of the white light generated from adigital monitor, such as a laptop computer monitor or a desktop computermonitor, is usually yellower than that generated from a TV, therebyresulting in less preferred images displayed by the digital monitor. Thetraditional method for adjusting color temperature or color tone is tochange the spectrum of the light generated from a light-emittingmaterial, which is complicated and also takes much time, therebyburdening the manufacturing cost.

SUMMARY OF THE DISCLOSURE

According to an embodiment of the present disclosure, a display deviceis provided. A display unit of the display device includes a lightemitting unit and a light converting layer disposed on the lightemitting unit. The display unit emits an output light under an operationof the highest gray level, and the output light has an output spectrum.An intensity integral of the output spectrum from 380 nm to 489 nmdefines as a first intensity integral, an intensity integral of theoutput spectrum from 490 nm to 780 nm defines as a second intensityintegral, a ratio of the first intensity integral over the secondintensity integral defines as a first ratio, and the first ratio isgreater than 0% and less than or equal to 7.5%.

According to another embodiment of the present disclosure, a displaydevice is provided. The display device includes a backlight unit, alight modulating layer, a light converting layer, and a firstpolarization layer. The light modulating layer is disposed on thebacklight unit. The light converting layer is disposed on the backlightunit. The first polarization layer is disposed between the lightmodulating layer and the light converting layer. A display unit isformed of at least a portion of the backlight unit, at least a portionof the light modulating layer, at least a portion of the lightconverting layer, and at least a portion of the first polarizationlayer, wherein the display unit emits an output light under an operationof the highest gray level, and the output light has an output spectrum.An intensity integral of the output spectrum from 380 nm to 489 nmdefines as a first intensity integral, an intensity integral of theoutput spectrum from 490 nm to 780 nm defines as a second intensityintegral, a ratio of the first intensity integral over the secondintensity integral defines as a first ratio, and the first ratio isgreater than 0% and less than or equal to 7.5%.

These and other objectives of the present disclosure will no doubtbecome obvious to those of ordinary skill in the art after reading thefollowing detailed description of the embodiment that is illustrated inthe various figures and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional-view schematic diagram illustrating a displaydevice according to a first embodiment of the present disclosure.

FIG. 2 is a schematic diagram illustrating an output spectrum of theoutput light of the display device of the present disclosure.

FIG. 3 is a chromaticity diagram illustrating points of output spectrumsof output lights with different first ratios and different secondratios.

FIG. 4 is a sectional-view schematic diagram of a first exemplifiedvariant of the light converting layer shown in FIG. 1 according to thefirst embodiment of the present disclosure

FIG. 5 is a sectional-view schematic diagram of a second exemplifiedvariant of the light converting layer according to the first embodimentof the present disclosure.

FIG. 6 is a sectional-view schematic diagram of a third exemplifiedvariant of the light converting layer according to the first embodimentof the present disclosure.

FIG. 7 is a sectional-view schematic diagram of a variant example of thethird exemplified variant of the light converting layer shown in FIG. 6.

FIG. 8 is a filtering spectrum diagram of various pigments.

FIG. 9 is a sectional-view schematic diagram of a fourth exemplifiedvariant of the light converting layer according to the first embodimentof the present disclosure.

FIG. 10 is a sectional-view schematic diagram of a fifth exemplifiedvariant of the light converting layer according to the first embodimentof the present disclosure.

FIG. 11 is a top-view schematic diagram of the light converting layershown in FIG. 10.

FIG. 12 is a sectional-view schematic diagram illustrating a displaydevice according to a second embodiment of the present disclosure.

FIG. 13 is a sectional-view schematic diagram illustrating a displaydevice according to a variant embodiment of the second embodiment of thepresent disclosure.

FIG. 14 is a sectional-view schematic diagram illustrating a displaydevice according to a third embodiment of the present disclosure.

FIG. 15 is a sectional-view schematic diagram illustrating a displaydevice according to a variant embodiment of the third embodiment of thepresent disclosure.

DETAILED DESCRIPTION

The present disclosure may be understood by reference to the followingdetailed description, taken in conjunction with the drawings asdescribed below. It is noted that, for purposes of illustrative clarity,certain elements in various drawings may not be drawn to scale.

It will be understood that when an element is referred to as being “on”another layer or substrate, it can be directly on the other element, orintervening elements may also be present. It will be understood that,although the terms first, second, third etc. may be used herein todescribe various elements, components, sub-pixels, units, and/or layers,these elements, components, sub-pixels, units and/or layers should notbe limited by these terms. These terms are used to distinguish oneelement, component, sub-pixel, unit and/or layer from another element,component, sub-pixel, unit and/or layer.

Referring to FIG. 1, FIG. 1 is a sectional-view schematic diagramillustrating a display unit of a display device according to a firstembodiment of the present disclosure. The display unit of the displaydevice 10 includes a light emitting unit 12 and alight converting layer14 disposed on the light emitting unit 12. The display unit could emitan output light OL. The light converting layer 14 can convert the inputlight IL (with input spectrum) into the output light OL (with outputspectrum). In the display unit of the display device 10, an input lightIL with an input color emitted from the light emitting unit 12 entersthe light converting layer 14, and the light converting layer 14 absorbsa part of the input light IL and converts the part of the input light ILinto a converted light CL with a converted color different from theinput color. Other part of the input light IL that is not absorbed bythe light converting layer 14 will penetrate through the lightconverting layer 14. Accordingly, the converted light CL and the otherpart of the input light IL is mixed with each other to form the outputlight OL. Therefore, the output light OL is emitted from thelight-emitting surface of the light converting layer 14, and the outputcolor of the output light OL is a mixture color of the input color ofthe input light IL and the converted color of the converted light CL. Inthis embodiment, the main wavelength range of the input light IL is lessthan the main wavelength range of the converted light CL. Furthermore,the output light OL has an output spectrum under an operation of ahighest gray level. For example, for an 8-bit-deep image, the highestgray level may be 255, but not limited thereto.

In this embodiment, the light emitting unit 12 may include aself-emissive blue light emitting diode (LED), such as micro-sized LED(inorganic, called micro-LED) or organic light emitting diode (OLED),and the input light IL emitted from the light emitting unit 12 can bedirectly turned on or off by a switch electrically connected to thelight emitting unit 12, such as thin-film transistor (TFT), but notlimited thereto. However, the light emitting unit 12 may be other kindsof self-emissive LEDs or non-self-emissive light sources. Also, thenumber of the micro-LED in the light emitting unit 12 is not limited,which may be one or plural. For example, the display device 10 mayinclude a substrate with a concavity, and one or more micro-LEDsgenerating the same spectrum may be disposed in the concavity since thesize of the micro LEDs is about micrometer-scale or smaller. In thisembodiment, the input light IL has a spectrum with a wave, which will bementioned as “input spectrum” hereinafter. The wave of the inputspectrum ranges from about 380 nm to about 489 nm, and the wave of theinput spectrum has an intensity peak (local maximum intensity) and afull width at half maximum (FWHM) value, wherein the intensity peak isfor example ranges from 447 nm to 449 nm, and the FWHM may range from 10nm to 30 nm, for example ranges from 17 nm to 19 nm.

The light converting layer 14 may include a quantum dot material, acolor filter material or a phosphor material, or combination of at leasttwo of those materials. When the light converting layer 14 includes thequantum dot material, the light converting layer 14 may include aplurality of quantum dots 14 a. The quantum dot material is made of asemiconductor nano-crystal structure, and can be any one or moreselected from CdSe, CdS, CdTe, ZnSe, ZnTe, ZnS, HgTe, InAs,Cd1-xZnxSe1-ySy, CdSe/ZnS, InP, and GaAs.

Referring to FIG. 2, FIG. 2 is a schematic diagram illustrating anoutput spectrum of the output light OL of the display device 10 of thepresent disclosure. Since the output light OL is emitted by mixing theconverted light CL with the converted color and the other part of theinput light IL with the input color, the output spectrum of the outputlight OL may include at least two waves, wherein one of the wavescorresponds to the wave of the input spectrum, and the other onecorresponds to the wave of the spectrum of the converted light CL. Inthis embodiment, the output spectrum of the output light OL has a firstwave W1 (sub), a second wave W2 (main), and a third wave W3 (sub). Thefirst wave W1 and the third wave W3 may represent the other part of theinput light IL that penetrates through the light converting layer 14,and fall in the range from 380 nm to 489 nm, as shown in the portion Iin the spectrum diagram in FIG. 2. In this embodiment, the first wave W1has a first intensity peak PK1 that is a maximum peak of the outputspectrum from 380 nm to 489 nm, and the third W3 has a third intensitypeak PK3 with the intensity less than the first intensity peak PK1,wherein the third intensity peak PK3 is at about 448 nm and correspondsto the intensity peak of the input spectrum of the input light IL asmentioned above, but not limited thereto. Because a large part of theinput light IL is absorbed by the light converting layer 14, the firstintensity peak PK1 with the maximum intensity in 380 nm to 489 nm isslightly different from the intensity peak of the input spectrum and isat about 478 nm. The second wave W2 represents the converted light CLgenerated from the light converting layer 14 and is in a range fromabout 490 nm to about 780 nm, as shown in the portion II in the spectrumdiagram in FIG. 2. The second wave W2 has a second intensity peak PK2that is a maximum peak of the output spectrum from 490 nm to 780 nm andfalls in the wavelength ranges from 535 nm to 540 nm. Since a large partof the input light IL is absorbed by the light converting layer 14, theintensity of the second intensity peak PK2 is much greater than theintensity of the first intensity peak PK1, and the output color of theoutput light OL can be similar to but not the same as the greenconverted color of the converted light CL. Also, through having thefirst wave W1 and the third wave W3 with less intensity, the outputcolor may be slightly bluish. In this embodiment, the green color of thesecond wave W2 is not mixed with other color except the blue color ofthe first wave W1 and the third wave W3.

Specifically, an intensity integral of the output spectrum from 380 nmto 489 nm, which is the intensity integral of the first wave W1 and thethird wave W3, defines as a first intensity integral I1. The firstintensity integral I1 may represent the energy of the other part of theinput light IL that is not absorbed by the light converting layer 14. Anintensity integral of the output spectrum from 490 nm to 780 nm, whichis the intensity integral of the second wave W2, defines as a secondintensity integral I2. The second intensity integral I2 may representthe energy of the converted light CL. A ratio of the first intensityintegral I1 over the second intensity integral I2 in the output spectrumdefines as a first ratio (I1/I2). The output color of the output lightOL can be determined based on the first ratio. In this embodiment, thefirst ratio is greater than 0% and less than or equal to 7.5%.Furthermore, a ratio of the first intensity peak PK1 over the secondintensity peak PK2 defines as a second ratio (PK1/PK2), and the secondratio can be greater than 0% and less than or equal to 10.0%. Thewavelengths of the second wave W2 at the FWHM may range from about 519nm and about 556 nm, so that the FWHM of the second wave W2 may be forexample 38 nm. When the light converting layer 14 includes the quantumdots 14 a for converting blue light into green light, the size of eachquantum dot 14 a may for example range from about 2 nm to about 4 nm.

Refer to FIG. 3 and Table 1, FIG. 3 is a chromaticity diagramillustrating points of the output spectrums of the output lights withdifferent first ratios and different second ratios, wherein the DCI-P3color gamut and the CIE 1931 color space are also shown in the diagram.The first ratios and the corresponding second ratios are listed in thefollowing Table 1. The curve CIE represents a boundary of the CIE 1931color space, and the region RG represents the DCI-P3 color gamut, inwhich the point DCIG represents the green primary color thereof of theDCI-P3. The point K0 represents the color of the second wave W2 with nofirst wave W1 and third wave W3, and therefore the point K0 is close tothe point DCIG enough to show almost the same color as the point DCIG,the green primary color. In addition, the point K1 represents thecondition of the first ratio being 1.1%; the point K2 represents thecondition of the first ratio being 2.2%; the point K3 represents thecondition of the first ratio being 3.3%; the point K4 represents thecondition of the first ratio being 4.4%; the point K5 represents thecondition of the first ratio being 5.5%; and the point K6 represents thecondition of the first ratio being 6.6%. Based on the above description,when the first ratio is greater than 0% and less than or equal to 7.5%or the second ratio is greater than 0% and less than or equal to 10%,the color of the points K1 to K6 may be adjusted to be slightly bluish,and at the same time, the color of the points K1 to K6 is still close tothe point DCIG enough to be used as a green light source, such as agreen sub-pixel. It should be noted that because the first wave W1 andthe third wave W3 are from the input light, the output color of theoutput light OL can be adjusted to be slightly bluish to match therequirements for the user or the end product. For example, when thedisplay device 10 is used as a light emitting cell in the greensub-pixel of a color display source, the white color generated from thered sub-pixel, the blue sub-pixel and the green sub-pixel of the colordisplay source can be slightly shifted to be bluish, thereby increasingthe color temperature thereof. Accordingly, the color temperature of thecolor display source or apparatus adopting the display device 10 can bethe same as the color temperature generated from the TV by adjusting thefirst ratio so as to improve the visual perception of the user. Inanother aspect, the display device 10 itself may be used as a displaysource for emitting single color, such as the green display source in aprojector, and the end image outputted by the projector with thecombination of the images produced by the display device 10 and othercolor display devices may also have a greater color temperature.

TABLE 1 Output spectrums of the output lights with different firstratios and different second ratios Point K6 K5 K4 K3 K2 K1 K0 First 6.6%5.5% 4.4% 3.3% 2.2% 1.1% 0.0% ratio Second 8.9% 7.4% 6.0% 4.5% 3.0% 1.5%0.0% ratio x 0.262 0.264 0.265 0.267 0.269 0.271 0.273 y 0.644 0.6520.659 0.667 0.676 0.684 0.693 Δx −0.003 −0.001 −0.000 −0.002 0.004 0.0060.008 Δy −0.046 −0.038 −0.031 −0.023 −0.014 −0.006 0.003

Referring to FIG. 4, FIG. 4 is a sectional-view schematic diagram of afirst exemplified variant of the light converting layer shown in FIG. 1according to the first embodiment of the present disclosure, whichexplains the light conversion mechanism of the exemplified lightconverting layer 141. In FIG. 4, as well as in FIG. 5 to FIG. 7, thesizes of the arrows respectively represent the light intensity. Thearrow marked by “ILB” represents the intensity of the blue input light,which is the input light IL in FIG. 1, the arrow marked by “CLG”represents the intensity of the green converted light, which is theconverted light CL in FIG. 1, and the arrow marked by “OLB⁺⁺” representsthe intensity of the blue output light (or called as blue-lightleakage), which is the other part of the input light IL not absorbed bythe light converting layer 14. The light converting layer 141 includesquantum dots 14 a which can convert blue light into green light.Therefore, the concentration of the quantum dots 14 a and the thicknessT1 of the light converting layer 141 influence the conversion rate. Asan example, the thickness T1 of the light converting layer 141 is, butnot limited to, about 100 μm, and thus the light conversion may not bevery high when the concentration of the quantum dots 14 a is not highenough. The intensity of the sum of the intensity OLB⁺⁺ and theintensity CLG is approximately equal to the intensity ILB, wherein theintensity OLB⁺⁺ is greater than the intensity CLG in this exemplifiedvariant embodiment.

The display device is not limited to the aforementioned embodiment, andmay have other different variant embodiments or embodiments. To simplifythe description, the identical components in each of the followingvariant embodiments or embodiments are marked with identical symbols.For making it easier to compare the difference between the firstembodiment and the variant embodiment and the difference between thefirst embodiment and other embodiments, the following description willdetail the dissimilarities among different variant embodiments orembodiments and the identical features will not be redundantlydescribed.

Referring to FIG. 5, FIG. 5 is a sectional-view schematic diagram of asecond exemplified variant of the light converting layer according tothe first embodiment of the present disclosure. As compared with thefirst exemplified variant embodiment shown in FIG. 4, the lightconverting layer 142 may include a multilayer structure. Specifically,the multilayer structure may include a plurality of quantum dot layers141L stacked in sequence, in which each quantum dot layer 141L includesa plurality of quantum dots 14 a. In this example, one or more of thequantum dot layers 141L are the same as the light converting layer 141shown in FIG. 4. The thickness T2 of the first light converting layer142 may be adjusted by the number of the quantum dot layers 141L andtherefore is greater than the thickness T1 of the light converting layer141. By adjusting the number of the quantum dot layers 141L, the firstratio mentioned above may be adjusted accordingly. As shown in FIG. 5,since the light converting layer 142 includes, but not limited to, threequantum dot layers 141L as an example, the green converted light in theoutput light has a total intensity three times the intensity CLG, whilethe intensity OLB⁻⁻ of the blue-light leakage is much less than theoutputted green light and much less than the intensity OLB⁺⁺ in FIG. 4.In addition, the thickness T2 is about 300 μm for instance.

Refer to FIG. 6, which is a sectional-view schematic diagram of a thirdexemplified variant of the light converting layer according to the firstembodiment of the present disclosure. As compared with the firstexemplified variant embodiment, the light converting layer 143 of thisvariant embodiment may further include at least one pigment material.Specifically, the light converting layer 143 may include a plurality ofpigment particles 14 b which can filter and absorb light of a specificwavelength range. Accordingly, through the pigment particles 14 b, thefirst intensity integral I1 shown in FIG. 2 may be changed or reduced,so as to adjust or lower the first ratio. In other words, because of thepigment particles 14 b, the thickness T3 of the light converting layer143 may be less than the thickness T2 in the second exemplified variantembodiment while maintaining the same intensity OLB⁻⁻ of the blue-lightleakage, or even maintaining the similar first ratio to the secondexemplified variant embodiment. For example, the thickness T3 may be,but not limited to, 100 μm. Depending on the characteristic of thepigment material of the pigment particles 14 b, the first intensity peakPK1 of the first wave W1 may be slightly changed or not. A size of eachof pigment particles 14 b, for example 50 nm, is greater than the sizeof each quantum dot 14 a, but not limited thereto. It should be notedthat the pigment materials or pigment particles 14 b mentioned in thisdescription may represent any material that can filter light or absorblight in specific range of light wavelength, such as dye or stain.

Referring to FIG. 8, FIG. 8 is a filtering spectrum diagram of variouspigments, which illustrates the filtering spectrums of yellow pigmentY150, green pigment G36, red pigment R254, and blue pigment B15:6. Sincethe wavelength of blue light is in a range from 380 to 489 nm, shown asthe range WLB in the figure, suitable pigment materials with suitableconcentration may be selected especially according to their filteringspectrums in the range WLB in order to adjust the absorption rate orintensity of blue-light leakage. For example, the transmittance of theyellow pigment Y150 is about 0.00 when the wavelength is less than 465nm, thus it can effectively absorb the blue input light with a mainintensity at 448 nm. In another aspect, the transmittance of the bluepigment B15:6 in the wavelength range from 430 nm to 470 nm is not reachto 1.00, and therefore the blue pigment B15:6 may be used for slightlyabsorbing the blue input light. Accordingly, one or more kind ofpigments may be adopted and doped in the light converting layer 143,based on the required first ratio and second ratio mentioned above.

Referring to FIG. 7, FIG. 7 is a sectional-view schematic diagram of avariant example of the third exemplified variant of the light convertinglayer shown in FIG. 6. In this variant example, the light convertinglayer 143′ may include quantum dots 14 a and plural kinds of pigments141 b, 142 b, 143 b, 144 b, such as blue pigment B15:6, yellow pigmentY150, red pigment R254, and green pigment G36 respectively, but notlimited thereto. The pigments in the light converting layer 143′ mayinclude two or more pigment materials, wherein these pigment materialsmay be selected from the above-mentioned materials or any other suitablematerial.

In another variant example, the light converting layer 143′ may includemultiple quantum dot layers doped with plural kinds of pigmentmaterials, wherein the different kinds of pigment materials may be dopedseparately in different quantum dot layers or in the same quantum dotlayers. In still another variant example, the light converting layer143′ may include multiple quantum dot layers with one kind of pigmentmaterial which is doped in one or more layers among the quantum dotlayers.

Referring to FIG. 9, which is a sectional-view schematic diagram of afourth exemplified variant of the light converting layer according tothe first embodiment of the present disclosure. The light convertinglayer 144 may include a first light-converting part L1 and a secondlight-converting part L2, and the second light-converting part L2 isdisposed (stacked) on the first light-converting part L1, in which thefirst light-converting part L1 includes a quantum dot material (shown asthe quantum dots 14 a), and the second light-converting part L2 includesat least one pigment material. In this exemplified variant embodiment,the second light-converting part L2 doesn't completely cover the firstlight-converting part L1, and the second light-converting part L2 mayinclude a plurality of portions P1, P2 separated from each other.Therefore, in the cross-section view, the width of the secondlight-converting part L2 is less than the width of the firstlight-converting part L1 in the light converting layer 144. The portionsP1, P2 includes a plurality of quantum dots 14 a and a plurality ofpigment particles 14 b respectively. For example, the portions P1, P2may be disposed near or on the edges of the first light-converting partL1 respectively. It should be noted that the pigment particles 14 b inthe portion P1 and the portion P2 may be different or the same, and thepigment particles 14 b may include only one pigment material or includemultiple pigment materials. In another variant embodiment, the portionP1 and portion P2 may not include the quantum dots 14 a. In addition,the total thickness T4 of the light converting layer 144 is the sum ofthe thickness T41 of the first light-converting part L1 and thethickness T42 of the second light-converting part L2, wherein thethickness T41 and the thickness T42 may be about 100 μm respectively,thus the total thickness T4 is about 200 μm and less than the thicknessT2 shown in FIG. 5. In another variant embodiment, the thickness T41 andthe thickness T42 may be about 50 μm respectively, thus the totalthickness T4 is approximately equal to the thickness T1 shown in FIG. 4while the light-converting layer 144 has less blue-light leakage thanthe light converting layer 141.

Referring to FIG. 10 and FIG. 11, FIG. 10 is a sectional-view schematicdiagram of a fifth exemplified variant of the light converting layeraccording to the first embodiment of the present disclosure, and FIG. 11is a top-view schematic diagram of the light converting layer shown inFIG. 10. Compared with the fourth exemplified variant embodiment, thesecond light-converting part L2 of the light converting layer 145 inthis exemplified variant embodiment has a first portion L21 includingquantum dots 14 a and pigment particles 14 b disposed on one side of thefirst light-converting part L1. The second light-converting part L2 mayselectively further include a second portion L22 disposed (stacked) onthe first light-converting part L1, the second portion L22 is adjacentto the first portion L21, and a combination of the first portion L21 andthe second portion L22 covers the first light-converting part L1. A topsurface of the first portion L21 may be leveled with a top surface ofthe second portion L22. The second portion L22 may include a transparentlayer without pigment materials or quantum dots. In another variantembodiment, the pigment particles 14 b may be formed of a plurality ofpigment materials. In still another variant embodiment, the firstportion L21 may not include the quantum dots 14 a. In another variantembodiment, the first portion L21 of the second light-converting part L2may not be stacked on the first light-converting part L1, but disposedaside the first light-converting part L1. In another variant embodiment,the light converting layer 145 may include a plurality of firstlight-converting parts L1 and a plurality of second light-convertingparts L2, and the first light-converting parts L1 and the secondlight-converting parts L2 are alternately stacked. It should be notedthat the arrangement and shape of the first portion L21 of the secondlight-converting part L2 is not limited to FIG. 11. For example, thefirst portion L21 may have a triangular shape or have in-continuouspatterns. In addition, the total thickness T5 of the light convertinglayer 145 is the sum of the thickness T51 of the first light-convertingpart L1 and the thickness T52 of the second light-converting part L2,and the thickness T5 may be greater than or equal to the thickness T1 ofthe light converting layer 141 in

FIG. 4 and less than the thickness T2 of the light converting layer 142in FIG. 5.

The above-mentioned display device 10 may be used as a display cell in asub-pixel of a color display device. Refer to FIG. 12, which is asectional-view schematic diagram illustrating a display device accordingto a second embodiment of the present disclosure. The display device 100is a color display device and may include a plurality of pixels PX, andeach pixel PX may include two or more sub-pixels for outputtingdifferent color lights. In this embodiment, the pixel PX includes threesub-pixels, and one of the three sub-pixels in one pixel PX may be agreen sub-pixel SPX1 that uses the display cell including the elementsin the display device 10 mentioned above in the first embodiment or itsrelated exemplified variant or variant embodiments. Specifically, thegreen sub-pixel SPX1 may include the light emitting unit 12 and thelight converting layer 14 so as to generate the first output light OL1with the green output color close to the green primary color of DCI-P3color gamut that meets the requirements. Wherein, the first output lightOL1 has an above-defined first ratio greater than 0% and less than orequal to 7.5%. Selectively, the first output light OL1 has anabove-defined second ratio greater than 0% and less than or equal to10.0%. The other two sub-pixels of the same pixel PX may respectively bea red sub-pixel SPX2 and a blue sub-pixel SPX3, but not limited thereto.The red sub-pixel SPX2 may include a second light emitting unit 22 and asecond light converting layer 24 disposed on the second light emittingunit 22. For example, the second light emitting unit 22 may be the sameas the light emitting unit 12, which is a blue LED, but not limitedthereto, and the second light converting layer 24 may include a quantumdot material, a color filter material or a phosphor material. The secondlight converting layer 24 can be used to absorb the light generated fromthe second light emitting unit 22 and generate another converted light,so that a second output light OL2 can be emitted from the second lightconverting layer 24. As compared with the light converting layer 14, theconverted light generated from the second light converting layer 24 isred. For example, the peak wavelength of the second light convertinglayer 24 may range from 633 nm to 639 nm, and when the second lightconverting layer 24 includes quantum dots, the size of each quantum dotmay be for example from 4 to 6 nm, but not limited thereto. Also, inorder to emit red light, the second light converting layer 24 shouldabsorb most of or all of the input light, so that the color of theoutput light OL2 from the second converting layer 24 can be close to orthe same as the red primary color of DCI-P3 color gamut.

Additionally, the blue sub-pixel SPX3 may include a third light emittingunit 32. For example, the third light emitting unit 32 may be the sameas the light emitting unit 12, which is a blue LED, but not limitedthereto. When the third light emitting unit 32 meets the requirements,the blue sub-pixel SPX3 may not include light converting layer. However,the blue sub-pixel SPX3 may selectively include a third light convertinglayer 34 disposed on the third light emitting unit 32 in order to meetsome requirements. The third light converting layer 34 may include aquantum dot material, a color filter material or a phosphor material.The third light converting layer 34 can also be used to change the bluelight of the third light emitting unit 32 to be close to the blueprimary color of the DCI-P3 color gamut. For example, when the thirdlight converting layer 34 is formed of the quantum dots, the size ofeach quantum dot may range from 2 nm to 3 nm. Also, the intensity peakof the converted light of the third light converting layer 34 may rangefrom 447 nm to 449 nm. The thickness of the third light converting layer34 may be less than the thickness of the light converting layer 14 andthe thickness of the second light converting layer 24. It will beunderstood that the display device 100 may further include other displayelements, such as data lines, scan lines, TFTs, electrodes, substrates,polarization layers, optical films, insulating layers, encapsulationlayers, or other elements or layers. The display unit may include atleast a portion of elements or layers, for example the red sub-pixelSPX1 may include the first light emitting unit 12, the first lightconverting layer 14, and a portion of a corresponding polarizationlayer. The shift effect of first ratio, second ratio, and color hue(x-coordinate value, y-coordinate value) by those elements and layersmay be ignorable, and the dominant effective factor are the lightemitting unit and the light converting layer. The output light could beregarded as the final visual light of the display device to the user(observer).

Refer to FIG. 13, which is a sectional-view schematic diagramillustrating a display device according to a variant embodiment of thesecond embodiment of the present disclosure. As compared with the secondembodiment, the display device 110 of this variant embodiment furtherincludes an insulation layer IN covering the pixels PX. The insulationlayer IN may be formed of an organic material, such as photoresistmaterial, or an inorganic material, such as silicon nitride or siliconoxide. When the insulation layer IN is formed of organic material, itmay be easy to flatten the top surface of the insulation layer IN. Whenthe insulation layer IN is formed of inorganic material, the insulationlayer IN may have better resistance, which helps to apply to touchdevices. In another variant embodiment, the insulation layer IN may beformed of a multilayer structure, and the multilayer structure may be astack of the organic material and the inorganic material.

Refer to FIG. 14, which is a sectional-view schematic diagramillustrating a display device according to a third embodiment of thepresent disclosure. As shown in FIG. 14, the display device 200 mayinclude a backlight unit BU, a light modulating layer LM, a first lightconverting layer 14 and a first polarization layer PL1. The lightmodulating layer LM may be for example a liquid crystal layer or aliquid crystal panel used for modulating the liquid crystal of thesub-pixels to different refractive states. It will be understood thatthe display device 200 may further include other display elements, suchas data lines, scan lines, TFTs, substrates, optical films, insulatinglayers, encapsulation layers, or other elements to control the switchesof the pixels. Specifically, the display device 200 may include a film Fwhich includes a plurality of the first light converting layers 14, aplurality of the second light converting layers 24 and a plurality ofselective third light converting layers 34 mentioned above. The firstlight converting layers 14, the second light converting layers 24 andthe third light converting layers 34 may be arranged alternately, and ablack matrix BM may be further disposed between any two adjacent lightconverting layers. In other words, the first light converting layers 14,the second light converting layers 24, the third light converting layers34 and the black matrix BM may form the film F. In other embodiments,the black matrix BM could be replaced by stacked light convertinglayers, or there is no black matrix BM. In this embodiment, the film Fis disposed on the backlight unit BU, and the first polarization layerPL1 and the light modulating layer LM is disposed between the backlightunit BU and the film F, in which the first polarization layer PL1 isdisposed between the light modulating layer LM and the first lightconverting layer 14. The display device 200 may further include a secondpolarization layer PL2 disposed between the light modulating layer LMand the backlight unit BU, so that the light modulating layer LM isdisposed between the first polarization layer PL1 and the secondpolarization layer PL2. The input light emitted from the backlight unitBU can be converted into output lights respectively by the first lightconverting layers 14, the second light converting layers 24 and thethird light converting layers 34. The backlight unit BU may generate theinput light the same as the input light of the first embodiment. Forexample, the backlight unit BU may include one or a plurality of lightemitting units 12 of the first embodiment. In the embodiment, a displayunit may include a light emitting unit (a portion of the correspondingbacklight unit BU), a portion of the corresponding light modulatinglayer LM, and a portion of the polarization layer(s). The shift effectof first ratio, second ratio, and color hue (x-coordinate value,y-coordinate value) by those elements and layers may be ignorable, andthe dominant effective factor are the backlight unit and the lightconverting layer. The output light could be regarded as the final visuallight of the display device to the user (observer).

Refer to FIG. 15, which is a sectional-view schematic diagramillustrating a display device according to a variant embodiment of thethird embodiment of the present disclosure. As shown in FIG. 15, ascompared with the third embodiment, in the display device 210 of thisvariant embodiment, the film F including the light converting layers 14,the second light converting layers 24 and the selective third lightconverting layers 34 is disposed between the backlight unit BU and thelight modulating layer LM. The first polarization layer PL1 is disposedbetween the film F and the light modulating layer LM, and the lightmodulating layer LM is disposed between the second polarization layerPL2 and the backlight unit BU. In the embodiment, a display unit mayinclude a light emitting unit (a portion of the corresponding backlightunit BU), a portion of the corresponding light modulating layer LM, anda portion of the polarization layer(s). The shift effect of first ratio,second ratio, and color hue (x-coordinate value, y-coordinate value) bythose elements and layers may be ignorable, and the dominant effectivefactor are the backlight unit and the light converting layer. The outputlight could be regarded as the final visual light of the display deviceto the user (observer).

It should be noted that the technical features in different embodimentsof the present disclosure can be combined, replaced, or mixed with oneanother to constitute another embodiment.

In summary, the first ratio and second ratio defined above can beadjusted easily by the thickness or the doped materials of the lightconverting layer to be greater than 0% and less than or equal to 7.5% inthe display device of the present disclosure. In another aspect, thenumber of the light-converting parts included in the light convertinglayer, the arrangements, shapes or areas of the light-converting parts,the concentrations, the sizes, or the materials of the quantum dots orthe pigment materials may also influence the above-mentioned first ratioand second ratio according to the present disclosure. As a result, thecolor temperature of the display device can be easily adjusted to besimilar to the color temperature generated from the TV, therebyimproving the visual perception of the user and saving the manufacturingcost.

Those skilled in the art will readily observe that numerousmodifications and alterations of the device and method may be made whileretaining the teachings of the disclosure. Accordingly, the abovedisclosure should be construed as limited only by the metes and boundsof the appended claims.

What is claimed is:
 1. A display device, comprising: a backlight unit; alight modulating layer disposed on the backlight unit; and a lightconverting layer disposed on the backlight unit, wherein a display unitis formed of at least a portion of the backlight unit, at least aportion of the light modulating layer, and at least a portion of thelight converting layer, wherein the display unit emits an output lightunder an operation of a highest gray level, the output light having anoutput spectrum, an intensity integral of the output spectrum from 380nm to 489 nm is defined as a first intensity integral, an intensityintegral of the output spectrum from 490 nm to 780 nm is defined as asecond intensity integral, a ratio of the first intensity integral overthe second intensity integral is defined as a first ratio, and the firstratio is greater than 0% and less than or equal to 7.5%.
 2. The displaydevice of claim 1, wherein the output spectrum comprises a firstintensity peak and a second intensity peak, the first intensity peak isa maximum peak of the output spectrum between 380 nm and 489 nm, thesecond intensity peak is a maximum peak of the output spectrum between490 nm and 780 nm, a ratio of the first intensity peak over the secondintensity peak is defined as a second ratio, and the second ratio isgreater than 0% and less than or equal to 10.0%.
 3. The display deviceof claim 1, wherein the light modulating layer is disposed between thebacklight unit and the light converting layer.
 4. The display device ofclaim 1, wherein the light converting layer is disposed between thebacklight unit and the light modulating layer.
 5. The display device ofclaim 1, wherein the light converting layer comprises a quantum dotmaterial, a color filter material, or a phosphor material.
 6. Thedisplay device of claim 5, wherein the light converting layer furthercomprises at least one pigment material.
 7. The display device of claim5, wherein the light converting layer comprises a multilayer structure.8. The display device of claim 5, wherein the light converting layercomprises a first light-converting part and a second light-convertingpart, the second light-converting part is disposed on the firstlight-converting part, the first light-converting part comprises aquantum dot material, and the second light-converting part comprises atleast one pigment material.
 9. The display device of claim 8, wherein ina cross-section view, a width of the second light-converting part isless than a width of the first light-converting part.
 10. The displaydevice of claim 8, wherein the second light-converting part comprises aplurality of portions separated from each other.
 11. The display deviceof claim 8, wherein the second light-converting part comprises a firstportion and a second portion, the first portion includes the pigmentmaterial, the second portion is a transparent layer, and the secondportion is adjacent to the first portion.
 12. The display device ofclaim 5, wherein the quantum dot material is made of a semiconductornan-crystal structure and includes one or more selected from CdSe, CdS,CdTe, ZnSe, ZnTe, ZnS, HgTe, InAs, Cd1-xZnxSel-ySy, CdSe/ZnS, InP, andGaAs.
 13. The display device of claim 5, wherein a size of the quantumdot of the quantum dot material ranges from 2 nm to 4 nm.
 14. Thedisplay device of claim 1, wherein the output spectrum has one wave in awavelength range from 490 nm to 780 nm and has two waves in a wavelengthrange from 380 nm to 489 nm.
 15. The display device of claim 14, whereinthe first intensity integral is a sum of intensity integrals of the twowaves in the wavelength range from 380 nm to 489 nm of the outputspectrum.
 16. The display device of claim 14, wherein a full width athalf maximum (FWHM) of the wave in the wavelength range from 490 nm to780 nm of the output spectrum ranges from 519 nm to 556 nm.
 17. Thedisplay device of claim 1, wherein the output light is green light. 18.The display device of claim 1, wherein the backlight unit produces bluelight.